Systems for sampling the air come in a variety of different configurations. Some air samplers collect an air sample for later analysis while other sensors provide both collection and testing of an air sample to determine the prevalence of target constituents. Still other air samplers particularly focus on the detection of a particular chemical or class of chemicals, either providing real time feedback as to the prevalence of target constituents in the air, or requiring laboratory testing to evaluate the prevalence of the target constituent.
While some chemical constituents in the air can be relatively easily identified through appropriate detector technology, other target constituents are less readily detectable, either because of the nature of the target constituent's chemistry or because the target constituent is present in exceptionally low quantities. When the target constituents can be readily detected, devices such as smoke alarms and carbon monoxide alarms are facilitated which can both sample for the target constituent, and when such a target constituent is detected, activate an alarm. When the target constituent requires more elaborate testing to accurately evaluate the prevalence of the target constituent, the sampler must capture a representative sample of air and then seal that sample effectively until it can be analyzed at an appropriate laboratory using testing criteria adapted for the detection of the constituents of interest.
Such air collection type samplers can in a simplest form merely be an enclosure which can be opened, purged, allow an air sample to pass therein and then closed to capture the sample therein. While such simple samplers are generally effective in capturing a sample of air, they are less effective when capturing target constituents that are present in very low quantities, or which might be present only during certain parts of the day and not always present.
Materials are known which selectively adsorb some chemical constituents more than others. When a particular target constituent is to be sampled, a material which preferentially adsorbs that material can be provided within a sealed sampler enclosure. A sampler enclosure can be opened and remain open for a set period of time. The material within such a sampler will selectively adsorb the target constituent in an amount corresponding with the prevalence of that constituent within the air. After the sampling interval is complete the sampler is sealed closed and the preferentially adsorbent material is analyzed in a laboratory. Through appropriate analysis and associated calibration; measurements, such as “parts per million” of the constituent to be measured, can be determined.
Such samplers which expose a material which preferentially adsorbs certain target constituents over a period of time, and then are returned to a laboratory for analysis are most preferable for the measurement of certain constituents and are the type of sampler to which this invention is primarily directed. Such samplers in one form are worn as a badge. The wearer attaches the badge to the wearer's clothing or otherwise wears the badge, such as suspended from a lanyard about the wearer's neck, and the badge travels with the wearer throughout the wearer's day. The sampler within the badge is continuously adsorbing the chemical for which the adsorbent material is preferentially configured. After a period of time has elapsed, such as one day or one week or one month, the sampler is returned to a laboratory and analyzed to determine how much of the constituent being sent has been gathered. This data can then be correlated to an overall amount of exposure that the wearer had to the particular chemical involved.
In one form, such badges include a sampler having an elongate rectangular body with a slide that slides from a lower end of the body to an upper end of the body. Holes are provided in an upper end of the body which pass into an interior of the body. A selectively adsorbent material or merely a material of generally adsorbent nature is contained within the interior. When the slide is in the lower position and the holes are exposed, air surrounding the body passes through the holes and constituents within the air are adsorbed. When the sampling interval is over, the slide can be slid to the upper end to cover the openings and preclude the adsorbent material within the interior from continuing to sense. In this way, the sampler is not contaminated by coming into contact with target constituents after the sampler has left the proximity of the wearer of the badge and before the collected sample is examined in the laboratory. One supplier of such air sampling badges is SKC Inc. of Eighty-Four, Pa.
One problem with such samplers is that when configured in the form of a badge, they cannot effectively monitor the air within a single location, but rather monitor exposure of the wearer to different chemicals. On occasion it is desirable to measure the prevalence of certain target constituents within a particular space, rather than having the sampler follow an individual. For instance, when purchasing a home it would be desirable to have an objective measurement of the prevalence of certain constituent chemicals or classes of chemicals within the home.
Accordingly, a need exists for a sampler which can effectively monitor the prevalence of certain target constituents within a particular space. Furthermore, it is desirable that such samplers be easily returned to a laboratory in a sealed fashion so that the sampler does not become exposed to target constituents when in transit back to the laboratory, and after the sampling interval is complete.